of wilmington



E. DU PONT.

PROCESS OF MAKING EXPLOSIVE BLACK POWDER.

APPLICATION men 056.29, 1915.

1,308,342. Patented July 1, 1919.

FIG.

II II wlmezs's: mew/70 WW. 9 0' FM 2AM W UNITED STATES PATENT OFFICE.

ERNEST DU PONT, OF WILMINGTON, DELAWARE, ASSIGNOR T0 BALL GRAIN EXPLO-SIVES COMPANY. OF WILMINGTON, DELAWARE, A CORPORATION OF DELAWARE.

PROCESS OF MAKING EXPLOSIVE'BLACK POWDER.

Specification of Letters Patent.

Patented July 1, 1919.

Application filed December 29, 1915. Serial No. 69,167.

To all whom it may concern:

Be it known that Erxnsr DU Pox'r, a citizen of the United States,residing at Vilmington, county of New Castle, and State of Delaware,have invented a new and useful Improvement in Processes of Makingllxplosive Black Powder. of which the following is a full. clear, andexact description. reference being had to the accompanying drawings.which form a part of this spcc1hcation.

It is well umlcrstood that the manufacture of black powder is more orless dangerous: explosions sometimes resulting during grinding andmixing, teclmicallyknown as im-orporation. and sometimes during theoperation of pressing and forming the cakes or grains. In the latteroperation the principal source of danger is undoubtedly the greatpressure-v21rying' from 1500 to 20M) pounds per square inch-requ1red toproduce the desired finished product. Further, this high pressureproduces such wear and tear of the parts in contact with the powder thatthey have to be replaced very frequently. I

The object of my invention is to so modity the process as to render theincorporating operation absolutely safe and to dispense with thenecessity of employing high pressure in the molding ot' the powder.thereby rendering this operation also absolutely safe and incidentallyavoiding the expense and delay involved in the frequent substitution ofparts of the press.

The practice of the process involving my invention does not require theuse of any special apparatus. but to aid inunderstandingof the process,I will describe the same in connection with the accompanying drawings.in which Figure 1 is a vertical sectional view of a grinding and mixingmill: Fig. 2 a similar view of a stirring tank: and Fig. 3 a similarview of a mold.

The mill shown in Fig. 1 is fully set forth and described in the duFont. and du lont application. Serial No. 807.374. tiled December 18.1913. and comprises a cylinder a revolublc on two pairs of wheels I, onepair of which is on a driving shaft 1', the cylinder containing twoheavy rollers 11- and having axial openings 0 in the ends communicatingwith the interior of a box surrounding the cylinder.

The solid ingredients of the explosive,

namely, niter (either nitrate of potash or nitrate of soda), sulfur andcharcoal, are ground together in the mill, which need not, however, beof the construction shown in the drawings. In place of water there isemployed a. liquid which has no solvent or chemical effect upon theingredients. Such a liquid is gasolene. The proportions of the solidingredients may vary somewhat, but a typical composition is onecontaining 75 parts by weight of nitrate of potash, 15 parts by weightof charcoal and 10 parts by weight of sulfur. The amount of gasolene orequivalent liquid added should he sutlicient to cover the mass andrender it fluid during the process of grinding. This amount will varywith the particular liquid used and it will also vary with conditions;but, as an example, it may be stated that with 100 parts of the abovemixture of solid ingrediei'its and with the grinding operation conductedat a temperature of 20 C., 100 parts by weight of asolene has been foundto sutlice. To the above mixture should be added water. say from 2.7 to3.0 parts by weight, which is the same amount of water added in theordinary so called dry process. The mill should be operated until allthe solid materials are thoroughly ground together.

The mixture is then removed to a tank 1 provided with a stirring deviceh. the latter operating to keep the solid materials in suspension in thegasolene. It will be under stood that no particular construction ofapparatus is necessary to carry out this step of the process.

Any measured quantity of the material that may be drawnofi' necessarilycontains a definite quantity of the powder mate'ials. and such measuredquantity so drawn off is poured into a mold and molded into a cake. InFig. 3 is shown a simple form of mold that will be found eflioacious.although no particular form of mold is essential. The same comprises atube i of metal of about one half inch internal diameter and twoplungers The phmgers should be about as good a tit as a machinist wouldnaturally make where free movement. of the plungers within the tube isdesired. It will be found that. the excrtion'ot a very slight pressure.such. for example, as can be exerted with comparatively light handpressure is sufficient to compress the powder to the extentdesirable andto squeeze out the gasolene or at least a large portion of it; the

minute. space between the tube i and the plungers j, incident tothejt'ree sliding tit between them. being sutlieient to allow thegasolene to escape.

The cake or rod of powder is then removed and dried at a tenq eraturesutlicient to drive off the remaining gasolene and the, water. Theproper temperature depends upon the time which it is desirable to takefor drying. Thus, if the temperature is high. say 100 t.. the dryingprocess takes but a very short time, but if the temperature is low. say50 the time required to expel the moisture from the inside of the cakeis relatively long.

Ypon close examination and thorough test. the powder is found to havephysical and other properties quite equal to. and in some respectssuperior to. those possessed by powder manufacturtal in any of the knownways and pressed in a heavy press under a pressure of from 1500 to .3000pounds per square inch. The molds will last indefinitely. the requiredpressure being so slight as to produce no appreciable wear and teal.

it will he understood that while other liquids having no solvent orchemical action upon the explosive ingredients may he used in place, ofgasolene. other liquids. such as alcohol. which is miscible with water.would he incapable of use. because they would prevent the water fromperforming its function.

While. properly speaking. the mold has no selective action ineliminating the larger part of the gasolene and not the water. the factis that only the gasolene will he therein eliminated. By reason of thesolvent action of the water it is held as a coating around the particlesof the material which it in part dissolves. Therefore. when the mass iscompressed in a mold which allows liquid to escape. or even should it bepoured on a filter. the inactive liquid alone escapes.

Having now fully described my invention. what I claim and desire toprotect by Letters Patent is:

1. The process of manufacturing explosive black powder which consists inincorporating the solid ingredients thereof with a liquid having nosolvent or chemical action upon the ingredients and with water and thenmolding the explosive.

2. The process of manufacturing explosive black powder which consists inincorporating the solid ingredients thereof with a liquid having nosolvent or chemical action upon the ingredients and with water of aweight less than that of said liquid. and then molding the explosive.

3. The process of manufacturing explosive hlack powder which consists ingrinding and mixing the solid ingredients thereof in the presencc of aliquid having no solvent or chemical action upon the ingredient and inthe presence of water, then stirring the mixture. and then molding theexplosive.

4. The process of manufacturin pellets of explosive powder whichconsists in grinding together the solid ingredientsthereof in a liquidwhich has no solvent or chemical action upon such of the ingredients asare to be ground. there being present a small per centage of a liquidhaving a solvent action on one ingredient and which therefore tends toresist dissociation therefrom, molding the. explosive in a mold whichpermits a portion of the inactive liquid to escape. and suh jecting themolded cakes to drying action at a temperature suflicient to dry offboth the inactive and the solvent liquid.

5. The process of manufacturing explosive black powder which consists inincorporating the solid ingredients thereof with a liquid having nosolvent or chemical action upon the ingredients and with water, thewater having a solvent action upon a part of the. powder and therebytending to resist dissociation therefrom. then pressing the explosive ina mold and thereby expelling from the explosive more or less of thefirst named liquid, and then drying the molded product.

6. The process of manufacturing explosive black powder which consists inincorporating thesolid ingredients thereof with a liquid having nosolvent or chemical action upon the ingredients and with water of aweight between 1:} and 3,; .percent. of the weight of said solidingredients 7. The process of manufacturing pellets of explosive powderwhich consists in grinding together the solid ingredients there oftogether. with from 1:} to 3. 5% of their weight of water..in gasolene.molding the powder in a mold from which the excess of gasolene canescape. the water hy reason of itssolvent action remaining inassociation with th powder. and subjecting the molded )elletto a dryingaction at a temperature sutlieient to remove the gasolene and the water.

8. The. process of mamlfactmring pellets of explosive powder. whichconsists in main taining the mass. which has been previously ground. insuspension by agitation in gasolene, and measuring out definite volumesof the gasolene so that definite weights of pellets may hepre-determined.

In testimony of which invention. I have hereunto set my hand, atvPhiladelphia, Penna. on this 27th day of December, 1915.

ERNEST DU roar.

tlopies of this patent may be obtained for five cents each, byaddressing the Commissioner of Patents.

Washington. D. c."

